For me, when i write an answer and I think of something funny to link to what I have to answer. Then definitely I would do so. It would create a kind of bond with the reader and relate to the reader. I guess humor is a universal kind of feeling if it is understood.
But sometimes, if the question needs a really serious answer, I would not add too much humor in it to make the answer more creditable. If it was full of funny punch lines. In musing, it is really important to sometimes add some humor as everything is more of a black and white format and these is a lot of imagination is required in making the post interesting.
Humor is also a form of intelligent thought. It is an art which usually needs a person to understand what makes it funny to the audience and not only to him/herself. Some people can talk about funny things but no one understands it.